摘要:

SUMMARY:Studies were made of the influence of heating on nucleotides and total purine nucleosides and bases of beef, pork and lamb muscle. lnosinic acid was the predominant nucleotide in all three species and it was degraded by heating. Adenylic acid increased during cooking in meat from all three species. Cytidylic, uridylic and guanylic acids were present in relatively low concentrations in meat from all three species and changed little during cooking. A rapid method for estimating total nucleotides resulted in greater variation than a specific method for measuring individual nucleotides.

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1970.tb12373.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARY:Cooking resulted in significant increases in adenylic acid, total purine nucleosides and bases of 80 beef roasts of eight different cuts. It decreased the contents of inosinic acid, guanylic acid and sum of individual nucleotides (adenylic, cytidylic, uridylic, inosinic and guanylic acids) in these samples. Significant differences were also found between the various constituents of raw and cooked samples of the beef cuts.

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1970.tb12374.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARY:Studies of the perchloric acid‐extractable nitrogen, amino nitrogen, nonamino nitrogen, total carbohydrates, inorganic phosphate, free creatinine, creatine and total creatine plus creatinine of raw and heated beef, lamb and pork were made. Specific changes that occurred in the various constituents during heating are discussed. An extensive study of the influence of heating on certain chemical constituents of 80 beef samples of eight different cuts was also performed. Changes in chemical constituents during cooking of the various beef cuts were greatest in Choice clod and Good calf clod roasts, followed by round roasts and smallest changes occurred in rib steaks. Cooking caused significant increases in creatinine and decreases in amino and non‐amino nitrogen, creatine and total carbohydrates. Creatine‐creatinine was a better index of sensory quality than other chemical constituents st

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1970.tb12375.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARY:A review of the theory and practice of the two‐stage triangle test for the sensory perception of small differences leads to the conclusion that its disadvantages usually outweigh its advantages. When the test is used its information content is difficult to assess; and a “least objectional” method, based on a scoring scheme and statistical significance procedures, is here pro

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1970.tb12376.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARY:Viable cells of each of 6 strains of Clostridium perfringens were exposed to 4 levels of acidity during phases of the growth cycle. The selected strains included 4 which had been recovered in association with food poisoning outbreaks and 2 strains not so associated. The growth media tested included Fluid Thioglycollate Medium, DS‐sporulation medium and the CP‐2V medium proposed by Hauschild.The level of acidity, length of exposure of the cells, the growth medium employed and the phase in the growth curve influenced the survival of C. perfringens. Exposure of cells grown in DS‐sporulation medium to buffers pH 6.0 had little effect on the survival over the 8‐hr test period, with somewhat greater sensitivity of cells being demonstrated at pH 4.5. Exposure of cells, similarly produced, to buffer pH 1.0 or 2.0 was much more effective in reducing the percentage of survival, particularly during early log phase and at the onset of sporulation. Based on the 3 growth media utilized, calculated survival curves resulting from exposure of cells to pH 1.0 or 2.0 were erratic in shape, and percentage survival was almost universally less than 10%.Source of the strain, whether food poisoning or non‐food poisoning associated, appeared to have no significant effect on the acid resistance of the cells. The comparatively regular increase in the percentage of survivors after the initiation of sporulation suggests that spores exhibit a greater resistance to acid stress than vegetative cells.Incubation at temperatures of 37° or O°C, during the time of treatment with the test buffers pH 1.0 or 2.0, produced no consistent change in the percentage of survivors when the cells were g

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1970.tb12377.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARY:Determinations have been made of the sensory odor threshold estimates of four alcohols, five esters, seven acids and diacetyl found in alcoholic beverages, by means of the triangular test. The threshold levels ranged among alcohols from 5 to 8 ppm except for isobutyl alcohol with the level of 75 ppm. Among esters there were three with the level of 0.2‐0.6 ppm and two with the level of 14‐17 ppm. Among acids three levels were found, one with the range of 4‐9 ppm, one with 15‐20 ppm and isovaleric acid with 0.7 ppm. Diacetyl had the lowest level–0.0025 ppm. The determination of thresholds was standardized by calculation of the percentage‐abovechance‐scores; by testing the usefulness of the amateur panel, and by specification of the threshold estimates in statistical terms. The results attained a fair goodness‐offit of the model and the smell perception was found to vary with the logarithm of the stimulus. The distribution of scores follows the normal proba

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1970.tb12378.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARY:Shear strength, sarcomere length and protein solubility were studied in rabbit longissimus dorsi allowed to pass through rigor in free and stretched physical states. Stretched muscles were significantly more tender as evidenced by lower shear values. They also exhibited significantly longer sarcomeres as compared to their paired controls allowed to pass through rigor without restraint. Greater amounts of total protein were extracted from stretched muscles in all trials except one. Significantly greater amounts of actomyosin were extracted from stretched muscles in all trials. The actomyosin results were unexpected since it has been suggested by several workers that actomyosin formation is directly related to toughness in muscle. Some possible explanations for the results obtained in this study are discussed.

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1970.tb12379.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1970.tb12352.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY